When a virtual computation machine defined on a computation machine is moved to another computation machine, information used in a process executed by the virtual computation machine is sent to an external storage device and then is moved to the other computation machine.
In a system including a plurality of server devices, each executing a process based on a request, session information included in a server device having a load larger than that of another server device is moved to another server device so as to decentralize the load.
When a process of a virtual computation machine operated on a computation machine is executed by a virtual computation machine on another computation machine, configuration information on a storage interface and the like of the original virtual computation machine is set in the virtual computation machine defined on the other computation machine, and then the virtual computation machine defined on the other computation machine is operated. For example, the original virtual computation machine is stopped and a new virtual computation machine is suppressed from starting an operation during a time period when configuration information is exchanged between the original virtual computation machine and the new virtual computation machine.
Examples of the related art include Japanese Laid-open Patent Publication No. 2009-145931, Japanese Laid-open Patent Publication No. 2007-219964, and Japanese Laid-open Patent Publication No. 2010-33404.